User-Defined Adaptive Fault-Tolerant Execution of Workflows in the Grid

In this paper, we propose and evaluate a framework for fault tolerant workflow execution in grid environments that dynamically chooses an appropriate fault tolerance technique with a user-defined rule-based system. In this first version, binary trees are used. We also provide a generic interface that can be used to add fault tolerance techniques to the framework. A prototype of our framework was implemented in Java using Integrade as the grid middleware. By now, the fault tolerance techniques Retry and Replication are implemented. The results obtained with 3 real workflows in an experimental grid environment show that the overhead introduced by our framework in a failure-free execution is small. Moreover, we show that, using our framework, workflows are able to execute successfully in the presence of failures and that the framework can dynamically choose an appropriate fault tolerance technique.